Alternating-current motor.



No. 839,401. PATENTED DEC. 25, 1906.

M. MILGH. ALTERNATING CURRENT MOTOR.

APPLICATION FILED JUNE 17, 1904.

2 SHEETSSHEET 1 Fig.2.

8M wcfgcemflch. E by PATENTED DEC. 25, 1906.

- M. MILOH.

ALTERNATING CURRENT MOTOR.

APPLICATION FILED JUNE 17, 1904.

2 SHEETS-SHEET 2.

milch 1 mauric by winding is at an angleto that ther increased UNITED STATES ELECTRIC OOMPA NY,

PATENT OFFICE.

MAURICE MILOH, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL A CORPORATION OF NEW YORK.

ALTERNATING-C URRENT MOTOR.

Specification of Letters Patent.

Patented Dec. 25, 1906.

Application filed June 17,1904. Serial No. 212,962.

To all whom it may concern:

Be it known that I, MAURICE MILoH, a subject of the Emperor of Austria-Hungary, residing at- Schenectady, county of Schenec tady, State of New York, have invented certain new and useful Improvements in Alternating-(jurrent Motors, of which the following is a specification.

"My invention relates to alternating-current motors of the commutator type in which the magnetic field produced bythe fieldproduced by the armature-winding. Mymvention consequently is particularly applicable to alternating-current series motors.

' In order to improve the elliciency and power factorof motors of this type, it has been proposed heretofore to short-circuit equipotential points on the field-winding.

he'short-circuiting connections form, with the field winding, closed circuits in inductive relation to the armature, and consequently act as short-circuited secondaries for the armature-winding, thereby improving the eHiciency and power factor of the motor.

y invention relates to motors provided with such connections between equipotential points; and is to provide a novel form of connections for such motors, whereby the field-windingis utilized to the best advantage, both for producing a field at an angle to that of the armature and also for neutralizing the self-induction of the armature.

A second object vof my invention is to so connect the field-winding that a commutat ing-field is produced for the armature. By this means the elficiency of the motor is furand the commutation is improved without the necessity of employing auxiliary commutating-coils.

My invention will best be understood by reference to the accompanying drawings, in Whicha Figure 1 shows diagrammatically the motor connected in accordance with my invention so as toutilize the field-winding to' the est advantage for producing the field magnetization andalso for neutralizing the armature self-induction. fication of the same. Fig. 3 shows an addi tional connection for the field-Winding for producing a commutating-field. Fig.

shows a modified arrangement of the fieldr Fig. 2 shows a modi- I winding, the portions for I armature self-induction being connected in produced by the armature-winding,

one object of my invention ably disposed for neutralizing the series with the armature instead of being short-circuited. Fig. 5 shows a development of a portion of a field-winding arranged and connected in accordance with my invention, and Fig. 6 is an explanatory diagram.

In the drawings, A represents the fieldwinding of an alternatin -current motor.

represents the armature-Winding provided with a commutator and commutatorbrushes b b. O represents a conductor connecting the equipotential points 0 c on the field-winding.

0 represents a similar conductor connecting the equipotential points 0 0.

Since the pointsc c are equipotential with respect to the magnetization produced by the field-winding, the short-circuiting connection O has magnetization. The

short circuit C, however, is parallelto the line of magnetization consequently forms, with the portion of the field-winding between the points 0 c, a closed circuit in inductive relation to the armaturewinding. This closed circuit acts as a short-circuited secondary to neutralize the self-induction of the armature, and thereby to increase the power factor and efficiency of the motor. It will be seen, moreover, that in Fig. 1 the short-circuiting connections C and O are utilized as the terminals of the field- Winding instead of employing field-terminals at two points displaced from each other by one hundred and eighty degrees. The current which fiows in at the motor-terminal a divides and passes through winding A between upper points 0 c and between lower points a c and from there to the commutator-brush 6, through the armature winding, out at brush 6 to the second motorterminal a; It is only the portions of the winding A between points 0 and c, which carry the exciting-current and whichserve to produce the field flux at an angle to that of the. armature. It will be seen that these portions of the fieldwinding are most favorproducing a field of uniform density facing the -armature-winding.

The other portions of field-winding A 'i. 6., those between points 0 and c and between c and ccarry only the current due'to the electromotive force induced in those pornodirect effect upon the field the portions of ture.

- entirely distinct.

' between the points c tions of the field-winding. These portions, moreover, are most favorably disposed for neutralizing the self-induction of the arma- Conse uently the several portions of the field-Win ing are utilized to the best'ad vantage both for producing the'field magnetization and for neutralizing the self-induction of the armature- Of course it is not essential that the two currents in the field-Winding should be kept The same portion of the field-winding may carry the whole or portions of both currents. Thus in Fig. 2 while only portions of the winding A are utilized for producing the field magnetization in the same manner as in Fig. 1 a third short-circuiting connection C is provided The portions of the field-winding that are active for producing the field magnetization consequently carry a portion of the compensating'current also in t e arrangement of Fig. 2. In Fig. 3 is shown an arrangement for causing the field-winding itself to produce a commutatin -field for the armature. e equi otentia points a c are connected to an auxi iary source of current, such as the trans former t, and a third current is thus introthe points 0 of the motor ing-fields are duced into the motor. The current entering at the upper terminal a divides, part passing in one direction to upper point 0 and part passing in the opposite direction t'o upper point 0. The two parts then pass through the short-circuiting connections C and C, res ectively, and in opposite directions through t e rest of the field-winding to the lower terminal 0 Thus it Will be seen that poles are produced at the points c 0 These poles are directly opposite the brushes b b, andconsequently 1f the potential impressed upon 0 is of the proper magnitude and phase an effective commutating-field will be produced, whereby the commutation will be greatly improve and the efficiency further increased. ing employed for producing the commutatthose most favorably located Furthermore, the insertion of the commutating electromotive force between terminals 0 0 does not interfere with the dampin action produced by this connection, but t e armature self-induction is neutralized in the same manner as by connection C in Fig. 2. The field-winding itself is thus made to perform the function of the commutating-coils disclosed in my application for Letters Patent, Serial No. 202,134, filed April 8, 1904. In this former application I have disclosed a number of arrangements for obtaining an electroniotive force of the proper magnitude and phase for pro ducing a suitable commutating-field, and although in Fig. 3 of the present'ap'plication I have shown. the commutating for this purpose.

It will be Y observed that the portions of the field-wind-' supplying rangements winding. It may electrol 1.

motive force derived from a transformer t, connected in shunt to the transformer T, the motor, it will be understood that any of the arrangements disclosed in my former application or any other suitable armay be utilized for obtaining a proper ma nitude and Iphase for the commutating e ectromotive orce.

It is not essential that the field-winding should be composed of a single continuous be divided into separate portions, if preferred, the pro er portions be,- ing utilized for producing the tion and the other portions being'short-circuited'to neutralize the armature self-induction, or, if preferred, the latter portions may bev connected in series with the armature instead of being short-circuited, the effect as regards neutralizing the armature induction being substantially the same. in both cases. Thus in Fig. 4 I have shown thefield-winding in four portions, two of which, A A, are coneld magnetizae 7 nected in parallel with. each other and in se-' ries with the armature to produce the field magnetization at an angle to that of the armature in the same manner as in the former arrangements. The other two portions A A, which in the former figures have been shown as portions of a continuous winding, are in this figure shown independent and instead of being short-circuited are connected in parallel with each other and in series with the armature-winding. The result as re. gards neutralizing the armature self-induction is the same as though these portions were short-circuited. V

- "In' Fig. 5 I have shown a development of a portion of a distributed field-winding arranged in accordance with my invention and adapted for a four-pole motor. The portion. of the winding shown is indicated in full lines in Fig. 6, while the remaining portion, which may form, with the portion shown, a con.-

tinuous winding or which may be independent thereof and which may be short-circuited or connected in series with the armature, is

indicated by the dotted winding A A in Fig. 6. a a represent the field-terminals, while 0 0 represent the terminals upon which is impressed the commutating -vol tage. By tracing out the winding between the terminals a and a it will be seen that the points" 0 .c are equipotential points on the winding.

The developed winding shown is only one of a large number of windings to which my invention is applicable, and the arrangement and connections of the motor-windings may be modified in various ways without departing from the spirit of my invention. I aim in the appended claims to cover all such modifications.

What I claim as new, and desire to secure by Letters Patent of the United States, i s- In an alternating-current motor, an arfield-winding, sai

mature-Winding tor and brushes, tions between e provided with a commutaand short-circuiting connecuipotential points on the .eq u1potent1al points on the field-winding,

d conductors the fieldwinding. v

3. In an alternating-current motor, an armature-winding provided with a commutaconductors connecting forming the terminals for points on the field-winding on lines paralle and brushes, an allel portions connected to produce amagnet- -portions connected to neutra to the line of magnetization produced by the armature-winding, said conductors forming the terminals for the field-winding.

4. In an alternating-current motor, an armature-winding rovided with-a commutator a field-winding having parizationat an angle to that produced by the armature-winding and havin its remaining Iize the self-induction of the armature-winding. 5 In an alternating-current motor, an armature-winding rovided'with a commutator and brushes, an a field winding having parallel portions connected toproduce amagnetization at an ahgle to that produced by the armature-winding and having its remaining portions connected to form closed circuits in lnductive relation to the armature-winding.

6. In an alternating-current motor, an armature-winding provided with a commutator and brushes, conductors connecting equipotential points source of current oints on the etween said conductors.

an alternatin current motor, an armature-winding provi ed'with a commutator and brushes, conductors connecting equi' otential points on the field-winding, an a source of current connected to points on the connected to equipotential field-winding midway between said conductors.

8. In an alternating-current motor, an armature-winding rovided with a commutator and brushes, a eld-winding havin parallel portions connected in series with t e armature. and arranged to produce a magnetization at an angle to that produced by the armaturewinding, and a source of current connected to equipotential points on said portions.

In an alternating-current motor, an ar mature-winding provided with a commutator and brushes, a distributed field-winding conconnections being utilized on the field-winding, and a portions of the field-winding nected in series with the armature, and a source of current connected to equipotential points on said winding to produce commutating-fields at said points.

10. In an alternatin -current motor, an armature-winding provi ed with a commutator and brushes, a field-winding having parallel portions adjacent to the brushes connected in series with the'armature and arranged to produce a magnetization at an angle to that produced by the armature-winding, and a source portions to produce a connnutatingfield for the armature-coils short-circuited by said'brushes.

11. In an alternating-current motor, an ar mature-winding provided with a commutator and brushes, a field-winding having parallel portions connected to produce a magnetization at an angle to that produced by the ar mature-winding and having its remaining portions connected to neutralize the self-induction ofthe armature, and a source'of current connected to equipotential points on the st-named portions to produce a commutating-field for the armature-coils short-circuited by the brushes.

12. In an alternatingmurrent motor, an armature-winding provided with a commutator and brushes, conductors connecting equipotential points on the field-winding so as to form closed circuits in inductive relation to the armature-winding, and a source of current connected to equipotential points on the field-winding between said conductors to produce a commutating-field for the armaturecoils short-circuited by the brushes.

'13. In an alternati -current motor, an ari ded with a commutator hand this 15th da of June, 1904.

MAURICE MILOH.

Witnesses: I

BENJAMIN B. HULL, HELEN ORFORD.

IIO 

